US287829A - Method of and means for retaining heat in steam-boilers - Google Patents

Description

(No Model.) 2 SheetsSheet METHOD OF AND MEANS FOR RETAINING HEAT IN STEAM OOOOO S.

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METHOD OF AND MEANS FOR NETAININGHBAT IN STEAM BOILERS.

No. 287.829. Patented. Nov. 6, 1883...

. Wain/66.666. Izvenim? UNITED STATES; PATENT" OFFICE.

GEORGE. CLEVELAND HICKS, OF CHICAGO, ILLINOIS.

METHOD OFAND MEANS FOR RETAINING HEAT IN STEAM-BOILERS.

SPECIFICATION forming part of Letters Patent No. 287,829, dated November 6, 1883. I

I Application filed Febrnary l l, 1883. (No model.) I

.To aZZ whom it may concern.-

I Be it known that I, GEORGE CLEVELAND HIcKs, a citizen of the United States, residing at Chicago, in the county of Cookand State and exact description of the improvements, sufficient toenable others skilled in the art to make and use the same.

Sunday, or at other times,,there is a large amount of heat stored in the water and steam' of the boiler, which heat it is highly desirableshould be retained as much as may-be, since the fuel and time necessary to raise the steam again to requisite pressure are by such; saving of the heat greatly lessened. Whether the practice be to bank the fires on the grates or to draw them entirely and begin afresh, it

is plain that to discontinue the furnace-fire usual construction, and at the front thereof,

for any long periodsuch as, for example, during the twelve hours over night, when, generally, steam-boilers are in disusemust, and in fact does, reduce the temperature of the water very greatly. Direct radiation of the. heat from the boiler is usually assigned asthe cause of this reduction in temperature and pressure; but I have found that a serious source of loss results from certain local cononly to lose it again when in contact with the I cooler walls of the exit-passages and chimneyof the exit-passages below it are enough cooler than the air or gases to absorb their excess of heat and to cause their return again in circuit to the boiler, whereas if the damper be open,

or there be none, the draft through the furnace will speedily reduce the temperature-of the water, and in the end fresh accessions of cold air from the mouth of the stack will pass into the interior, to commingle with the local gaseous currents established therein, and to stillfurther absorb the heat.

My inventionis designed to retain the heat of steam-boilers while in temporary disuse; and it consists, specifically, in a method of and means for suppressing the aforesaid local convection-currents, all as hereinafter de- When steam-boilers are in temporary dis-v use at the close of the working day or over scribed, and more particularly pointed out in the claims following.

In the accompanying drawings, designed to illustrate the manner of applying my inven tion inpractice, like letters of reference indicate like parts.

Figure 1 shows a steam-boiler having a tubecloser in two parts attached thereto. Fig. 2 is a perspective view of the tube-closer. Fig. 3 shows a return-fiueboiler with the tube-closer applied thereto.

Within the casing of a boiler, B, of any where the gases emerge from; the boiler tubes or flues into the bonnet or exit-passage lead= ing to the chimney-stack, is arranged a tube closer, P, which may consist of a metal plate having a fire-resistantlining, of asbestus, fireclay, or the like, or may be made of any othermaterial suitable. to resist the action, of the highly-heated gases.- In the present instance the tube-closer P is provided with the rods R, to sustain the same, extending therefrom into ing-rod, H which pas es through the boilercasing to; the. exterior, and has a handle, H, by means whereof. the position of the closingplate P with "respect to the exit ends of the gtube'closer P should .be large enough to completely cover the front ends of the boiler flues or tubes opening into the bonnet or stack when said closer is forced against the educts or ports;

designed toeffectually close the ports or educts that are in position opposite thereto.

In the return-flue boiler shown 'in Fig. 3 F designates the fire-box, W the bridge-wall, and A the boiler-front, with its doors opened, so

that the tube closers P may be seen in position.

the tubes T of the boiler and with an adjust boiler tubes or flues may be adjusted. The

and for convenience the closer may be in two parts, as shown in Fig. 1, each section being \Vhile the boiler is in full use the tube-closer P will be drawn away from the ends of the tubes or flues, so as not to interfere with the draft; but when the furnace-fires are banked or drawn during any period of temporary disuse of the boiler, then, in order to maintain the water of the boiler in highly-heated c011- dition, the ash-pit doors may be closed and the tube-closer P is pushed against the ends of the flues or tubes, so that the objectionable local circulation of the gases is prevented.

Vhatever may be the special construction of the boiler or of the tube-closer, and however the same may be supported in place, it is obvious that the essential point to be observed is that the closer shall be in such relation to the educts of the boiler tubes or flues as to effectually check the establishment of local convection-currents in the air or gases, which otherwise would abstract the heat from the water of the boiler, to lose it again in the coolerpassages or stack, and then return to the boiler fiues or tubes, to take up fresh portions of heat. If the furnace-fires are banked on the grates, it will be found desirable to make the tubecloser in two parts, as shown, because by this means the lower section thereof maybe tightly shut against the educts of the dues or tubes, to check the cold convection-currents while the upper section may be left slightly open, to allow moderate ventage for the gases evolved from the coals, until such time as the smothered fire has cooled so far that evolution of the gases practically ceases, whereupon the upper section of the tube-closer may be shut down entirely, to arrest all further circulation, and this, too, without risk of any obnoxious gases being forced out into the furnace-room. Where the fires are drawn at the outset, it is obvious that no such precaution need be observed, and the closer can be madein one piece, or in sections, as desired.

Practical experience has demonstrated that in boilers having the local convection-currents suppressed, as described, the water of the boiler is maintained in ahighly-heated condition much more effectually than where no such precaution is taken. I11 the morning the gage shows but little reduction in steam-pressure, and not more than one-fourth of the time or fuel need be consumed in bringing the boiler to standard working-pressure that was usual prior to the adoption of the invention. Again, where the fires are banked, the closer not only arrests the convection-currents, but checks the draft, so that the risk of excessive pressure on the boiler, due to any unguarded freshening of the fire, is avoided.

It is plain that the heat and pressure being kept within more equable limits by the use of the invention reduces the severe strains on the boiler plates and rivets, to which the extreme changes in temperature heretofore customary made the boiler singularly liable. The security of the boiler'structure is consequently increased.

I am well aware that tube-stoppers to permanently plug up defective flues in steamboilers have been used, and that it is old to provide adjustable dampers, valves, or plates at the ends of the boiler flues or tubes for the purpose of regulating the draft through the flue-passages, or for directing the gases through some portions-of the tubes or flues more than through others, so that the heat shall be evenly distributed; but these objects are wholly foreign and without analogy to any had in view by me. They pertain to the use of the boiler in full working condition, and while it is being constantly fired, whereas my invention is designed to save the heat stored in the water of the boiler while the furnace is temporarily at rest, and is intended to check and suppress a class of local gaseous currents, which are of no moment, if, indeed, they canbe said to exist, save at such periods of temporary disuse.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. The method of retaining the heat of steam-boilers when in temporary disuse, which consists in suppressing the circulation of local gaseous currents between the boiler tubes or fines and the cooler-escape passages or chimney-stack, substantially as described.

2. The combination, with the boiler B, having the tubes T, of the adjustable plate tubecloser P, provided with the rods R and H, to sustain the same in front of the exit-fines, substantially as described.

GEORGE CLEVELAND HICKS. \Vitnesses:

WILL R. OMOHUNDRO, V. ROSSITER.

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